Internal siphon gauge



Oct. 24, 1939. E, H, BAYHA 2,177,200

INTERNAL SIPHON GAUGE Filed Jan. l2, 1937 Patentedct. 24, 1939 INTERNAL SIPHON GAUGE Edwin H. Bayha, Upper Darby, Pa., assignor to o United States Gauge Company, New York, N. Y.,

a corporation of Pennsylvania Application .ianuary 12, 1937, Serial No. 120,271 ,2 claims. (ci. 73-109) 'ment.

This invention relates to pressure gauges of the type wherein it is desirable or necessary to provide means for preventing the internal parts of thegauge, particularlythe pressure responsive element and any fusible joints, from being subjected to excessively high temperatures.

In gauges of this type; for example, gauges employed to measure the pressures of high pressure steam, it has been the practice to provide some means accomplishing the aforementioned result and one device commonly used was the conventional pigtail siphon comprising a looped tube forming a. condensate trap placed in the pressure line between the fluid source and the socket or base portion of the gauge. This device was positioned externally oi the gauge and thereioreiopen to several objections, principally that it was unf sightly in appearance and, dueto its location, eX-

posed .to damaging shocks or blows. It was hence Yproposed to place the Siphon or Vcondensate trap Within the gauge casing thus concealing it from View and protecting it from injury.

Previous devices of this kind usually involved va great deal of eXtra tubing, occupying considerable space .within the gauge casing and also interfering .with the other parts of the gauge mechanism, as Well asjrequiring numerous soldering operations. rFurthern'iore they generally failed to provide a trap of adequate capacity for the desired purpose or Were of insufficient surface area to promote condensation so as to insure an adequate body oi liquid in the trap. The present invention provides an internal trap which obviates'these diiiiyculties and accomplishes this desired result by means of a very compact devicewhich does not interfere with the usual gauge structure in any manner, nor ldoes it require a large. amount of extra tubing or involve numerous soldering operations. At the same time the trap is of sufcient volume and has adequate surface area to promote condensation.

A primary object, therefore, oi my invention is to provide, in a pressure gauge, an improved internal siphon or trap which is eflicient in operation, neat in appearance, simple and compact in construction, requires no radical or costly changes inthe usual gauge structure andis readily adaptable to various existing types or designs of pressure gauges. o

Another object of my yinvention is to provide an internal siphon or trap which is of adequate volume to insure against the entry of high ternperature steam into the pressure responsive ele- `A yiurther object of A'my invention isto provide an improved Siphon or trap which is constructed with thin walls to insure proper condensation and an adequate body of liquid therein.

Another object of my invention is to provide a Siphon or trap so arranged and constructed as to v5 provide a body of liquid adjacent to all joints formed o soft solder or other low melting point metal whereby the danger of loosening the same by contact with high temperature steam therewith is obviated. l0

A still further object of my invention is to provide a novel and simple arrangement of ducts within the usual base or supporting member for connecting the siphon or trap with the source of fluid pressure and with the pressure responsive 1 5 element.

These and other objects will appear from a study of the following detailed description and its appended claims when taken in conjunction with the accompanying drawing, wherein: v 20 Figure l is a front elevation of a gauge of conventional design embodying my improved Siphon or trap and wherein the usual dial, pointer and movement mechanism have been omitted forthe sake of clarity;

Figure 2 is an enlarged sectional view of my improved siphon or trap;

Figure 3 is a sectional view of Figure 2 taken on lines 3 3 of Figure 2, looking in the direction of the arrows;

Figure 4 is a side elevation of Figure l, with the casing and Bourdon tube removed, looking from the right; and y Figure 5 is an end elevation of Figure l, with the casing and Bourdon tube removed, looking yfrom the left and with the trap tube shown in dotted lines.

With continued reference to the drawing wherein like numerals are employed to designate like parts, and with particular reference to Figures 1 and 4:

The numeral I 0 designates a casing member which is suitably secured to a socket member l2 provided with a forwardly projecting base or supporting portion I3 and a rearwardly extending 45 boss portion 29, threaded as at 22. A Bourdon tube M or similar pressure responsive element is secured within a socket or opening I6 on the base portion and extends upwardly therefrom in an arcuate manner as shown in Figure 1.

The socket member I2 is provided with threaded bosses 24 to receive the casing securing screws and also with a forwardly projecting portion 26, which with the front face of the base portion I8 serves as a support for the usual dial, not shown. ,55

through the threaded boss 2li.

Socket member I2 is also provided with bosses 21-27 designed to support the usual movement mechanism and pointer, not shown, which is operatively connected to the pressure responsive element I4 by means of the apertured element l5, the latter element also serving as a closure for the free end of the pressure responsive element.

Directly below the opening Iii is an elongated opening or socket 28,l in which is secured one end of a tubular element forming a portion of my improved siphon or trap. The pressure responsive element I4 and the tubular element 3i) may have their lower ends secured to the base and within the sockets i6 and 23 in any suitable manner but a joint of soft solder is conveniently used for this purpose. The element 3Q is constructed of relatively thin-walled tubing for reasons which will appear later and preferably is curved similarly to the pressure responsive device i4 but is of considerably larger cross-section. This element is preferably shaped as shown in Figure 3, but other shapes may of course be used. The tubular element 3l] is located entirely within the casing lil and extends upwardly therein to a point well above the openings I and 28. At its upper end element 30 is closed by any suitable means, such as the plug 32, which may be secured and sealed in place for example by brazing or by solder sufficiently hard to resist the temperature of the pressure fluid.

Positioned Within the trap element 3i) is a smaller tube 34, which extends upwardly therein to a point closely adjacent the closed end of element 3G. At its lower end the tube 34 is received within a passage 35i opening into the socket 23 near the rear thereof as viewed in Figure 1 and is secured therein by soft solder or equivalent means. This passage 36 connects with a passage 4l), Figure 1 which extends backwardly The threaded boss 2B is intended to be secured to a pipe leading from a fluid pressure source and may also serve as a supporting means for the gauge.

In front of tube 34 andthe passage 36 is a vertical passage 42, plugged at its lower end as shown, and communicating adjacent its upper end with the pressure responsive device I4 through a passage 44 and the socket I6, and at its lower end with the tubular element 3l! through the passage 46 and socket 28. rI'he passages 36, 4Q, 42, 44 and 46 are conveniently formed by suitable drilled holes as illustrated, but they may be formed in any other suitable manner. The preferred arrangement of the passages as shown is of course variable within certain vlimits as long as proper connections are provided between elements i4, 39, S4 and the passage 4&1.

The tubular element Si! should be of sufiicient size to provide a volumetric capacity, exclusive of the space occupied by the tube 34, approximately equal to that of the pressure responsive deviceto insure that high temperature steam will not enterV the pressure responsive device. This volumetric capacity is readily variable to suit different conditions by varying the cross-sectional area or length of element 30.

The operation of my device is believed to be obvious from the foregoing but is briefly, as

follows:

Steam, or other iiuid under pressure, enters the gauge through the passage 4c, owing through passage 36 into the tube 34, which is preferably of small diameter and thus assists in condensation by virtue of the decrease in velocity of the steam and expansion thereof when passing therefrom into the much larger tube 36. From the upper end of tube 34 the fluid is discharged into the larger tubular element 36 Where,7 if the fluid be steam, it condenses into water which eventually lls the tubular element 36, as Well as the passages 42, 44, 4% and the Bourdon tube `vor pressure responsive element i4 at least up to the level of the upper end of tube 34, as shown in Figure 1. The fluid pressure is transmitted through this body of liquid to the pressure responsive element and registered by the gauge mechanism (not shown) in the usual manner. However, the large body of liquid contained within the siphon or trap, formed by the tubular element 30, passages 42, 44, 46 and the lower portion of the Bourdon tube i4, effectively preventsl high temperature steam from entering into the Bourdon tube or pressure responsive device and also fully protects all of the'soft soldered joints by keeping the same from contact with said high temperature steam. The thinness and large area of the wall structure of the tubular element 3l) greatly enhances condensation, which is also assisted by the small diameter of tube 34, as above explained, whereby rapid and sucient condensation of the steam is assured. f

While I have shown my improved trap or siphon in a gauge of the so-called low back connection type it is of course obvious that the same may be embodied in any other type of gauge, whether the point of entry of the pressure fluid be through the bottom, top, or front of the gauge. It is likevviseobvious that the exact position of the trap Within the gauge casing be varied` without changing the operation thereof or departing from the spirit of my invention.

Thus it is seen that I have provided a novel and improved trap or siphon tube arrangement for gauges which is compact and of suflicient size and proper design to function properly, contained entirely within the casing, simple in construction and requiring no costly modication of usual gauge structure. Y n

My invention may be embodied in other specific forms Without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description,

and all changes which come Within the meaningv and range of equivalency of` the `claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is: Y r1. In a gauge of the type described, a base portion provided with two vertically spaced elongated openings, a pressure responsive device p0- sitioned within the upper of said openings, a thin Walled tubular element positioned within the k other of said openings and extending upwardly adjacent to and outside of said device, said tubular element being closed at its upper end, means for securing said device and said element within their respective openings comprising a metal .of relatively low melting point, a second tube positioned Within said tubular element and having an open end adjacentthe upper end of said element, a passage in said base portion opening into said other elongated opening and receiving the other end of said second tube, a second passage means in said base portion leading from said first named passage to the exterior of said base portion for connection with a source of .uid pressure; and a third passage in said base portion connecting said .elongated openings; said tubular element, said ing upwardly adjacent to said pressure responsive tube for an appreciable distance; a third and smaller tube arranged within said second tube and extending into said last-named opening; said base portion being provided with a passage opening into said last-named opening and receiving said third tube; said passage extending to the exterior of said base portion or connection to a source'of fluid under pressure; and a second passage in said base portion connecting lo said openings.

EDWIN H. BAYI-IA. 

